ClearType: frequently asked questions

Applies to Windows Vista

ClearType is a technology for displaying computer fonts so that they appear clear and smooth. ClearType makes on-screen text more detailed and, therefore, easier to read for long periods of time without experiencing eye strain and mental fatigue. It works especially well when you're using LCD devices, including flat-panel monitors, mobile PCs, and smaller hand-held devices.

ClearType is turned on by default in Windows. But if for any reason it's turned off, you can turn it back on.

To turn on ClearType

Open Appearance Settings by clicking the Start button , clicking Control Panel, clicking Appearance and Personalization, clicking Personalization, and then clicking Window Color and Appearance. If the Appearance Settings dialog box is not displayed, at the bottom of the page, click Open classic appearance properties.

Click Effects.

In the Effects dialog box, select Use the following method to smooth edges of screen fonts.

Click ClearType in the list, and then click OK.

Note

Whether you select Standard or ClearType from the list, you must have a video card and monitor that support a color setting of at least 256 colors. You'll get the best results with High color (24-bit) or Highest color (32-bit) support. You can change color quality in Display Settings in Control Panel.

Open Display Settings by clicking the Start button , clicking Control Panel, clicking Appearance and Personalization, clicking Personalization, and then clicking Display Settings.

ClearType was developed to make it possible to read on-screen text for longer periods of time. There's a big difference between reading many printed pages and reading the same amount of text on a computer screen, and researchers wanted to determine why. So they explored what typographical qualities allow the human eye and mind to recognize letters and transform them into words, sentences, and—ultimately—meaning.

They found that for reading to be sustainable, it needs to be a largely unconscious activity. If letters are too jagged or don't flow together into easily recognizable patterns, the reader becomes more focused on the individual characters and is distracted from grasping the overall meaning of the text. This is why on-screen reading can be tiring. ClearType smooths the appearance of letters so readers can focus on ideas rather than having to concentrate on the display.

To understand how ClearType works, you should first understand a little bit about on-screen graphics. Screen displays consist of pixels. Pixels also make up the different letter styles in each font.

Every pixel in a font has three parts: red, blue, and green.

ClearType improves resolution by turning on and off each of the colors in the pixel. Before ClearType, the entire pixel had to be turned on and off. This tighter control over the red, blue, and green fractions of a pixel can increase the clarity on an LCD monitor by up to 300 percent.

You can use either type of monitor, but you'll get the most benefit when you use an LCD monitor. This is because ClearType was made to work with LCD technology, which keeps specific pixels in specific places. ClearType takes advantage of pixels being in a fixed place by turning fractions of the pixel on and off. A CRT monitor doesn’t work in the same way with ClearType because it uses an electron beam to excite, or move around, pixels, instead of keeping them stationary.

Still, you might experience some improvement in clarity when you use ClearType on a CRT monitor because ClearType smooths jagged font edges. This is called antialiasing.